Method of making perfluorinated phosphate esters and resulting new chemical compounds



METHOD OF MAKING PERFLUORINATED PHOS- PHATE ESTERS AND RESULTING NEW CHEMI- CAL COMPOUNDS James Carroll Conly, East Paterson, N.J., assignor to Douglas Aircraft Company, Inc., Santa Monica, Calif.

No Drawing. Application October 25, 1954 Serial No. 464,622

Claims. (Cl. 260-461) This invention relates to a method of making certain perfluorinated tri-alkyl phosphate esters represented by the formula (C F PO in which n is any integer from 3 to 8, that is, the alkyl radicals have from 3 to 8 carbon atoms and other resulting new chemical compounds.

This application is a continuation-in-part of my application Ser. No. 188,264, filed October 3, 1950, now abandoned.

In accordance with my invention described and claimed in my Patent No. 2,727,058 the discovery has been made that the fluorinated and chlorinated phosphate ester represented by the formula (C F CCl PO in which n is any integer from 3 to 8 can be made by chlorinating the corresponding phosphate ester represented by the formula (C F CH P0 in which n is any integer from 3 to 8, and that by this process new chemical compounds can be made represented by the formula (C,, F CCl PO in which n is any integer from 3 to 8.

In accordance with my invention as disclosed and claimed herein I have discovered that from such fluorinated and chlorinated phasphate esters the corresponding perfluorinated phosphate ester can be made, that is, the corresponding phosphate ester with all of the hydrogens of the :alkyl groups replaced by fluorination as represented by the formula (C F PO in which n is any integer from 3 to 8 and that by this method entirely new chemical compounds are produced as represented by this formula. This replacement of the chlorine atoms with fluorine atoms in accordance with my invention is done by an agent effective to make such a substitution such as COF3, AgF CUF2, SbF5, SbF3C12, etc. OI hydrogen fluoride, in either liquid or gaseous state, and

-at moderate or elevated temperatures, substantially as known in the art for eifecting substitution of fluorine for chlorine in organic compounds. My invention will be illustrated by the following examples:

Example I Tris-heptafluorobutyl phosphate was first made by the reaction of heptafluorobutyl alcohol with phosphorus to form a slurry-like mixture. The mixture was saturated United States Patent 0 at 0 C. with chlorine gas and then stirred under an ultraviolet lamp. The reaction required about 45 minutes to remove the chlorine as evidenced by the disappearance 2,898,364 Patented Aug. 4, 1959 of the yellow color. This procedure with the chlorine was carried out until the chlorination was complete. The reaction mixture was filtered and the clear liquid filtrate was distilled. The product was collected at approximately 135 C. at 1 millimeter Hg pressure, which is the approximate boiling point of this product. This product was tris-l,1-dichloro-2,2,3,3,4,4,4-heptafluorobutyl phosphate, as determined by analysis.

Example 11 The chlorinated phosphate tris-l,l-dichloro-2,2,3,3,4,4, 4- heptafluorobutyl phosphate is moved and reacted with CoF at a temperature of 280-300" C. with stirring until the reaction of substitution of chlorine with fluorine is complete, as indicated by no further replaceable chlorine. The product is purified to obtain the desired product tris-l,1,2,2,3,3,4,4,4 nonafluorobutyl phosphate.

The products made in accordance with my invention have a high degree of fire-resistance and are capable of imparting a high degree of fire-resistance to other materials or fluids into which incorporated.

The foregoing describes my invention in its preferred aspects, and illustrates my invention by way of specific examples, but alterations and modifications may be made thereof without departing from the invention herein disclosed.

Having described my invention, I claim:

1. The method of making a perfluorinated trialkyl phosphate ester represented by the formula in which n is an integer from 3 to 8 which comprises reacting the corresponding fluorinated and chlorinated phosphate ester represented by the formula in which n is an integer from 3 to 8 with a member selected from the group consisting of CoF AgF CuF SbF and SbF Ol until all the chlorine atoms in said ester are replaced with fluorine atoms. 7

2. The method as defined in claim 1 wherein said perfluorinated' trialkyl phosphate ester is 1,1,2,2,3,3,4,4, 4-nonafiuorobutyl phosphate and said corresponding fluorinated and chlorinated phosphate ester is tris-1,1-dichloro-2,2,3,3,4,4,4-heptafluorobutyl phosphate.

- 3. The method of making tris-l,1,2,2,3,3,4,4,4nona fluorobutyl phosphate which comprises fluorinating tris- 1,1-dichloro-2,2,3,3,4,4,4-heptafluorobutyl phosphate by reacting with cobalt trifluon'de at a temperature of about 280-3 00 C. until the substitution of chlorine with fluorine is complete.

4. The perfluorinated trialkyl phosphate ester represented by the formula (C F PO in which n is any integer from 3 to 8.

5. Tris-1,1,2,2,3,3,4,4,4-nonafiuorobutyl phosphate.

References Cited in the file of this patent UNITED STATES PATENTS 2,559,749 Benning July 10, 1951 2,694,083 Moreton et a1. Nov. 9, 1954 2,727,058 Conly Dec. 13, 1955 OTHER REFERENCES Fluorine Chemistry, vol. I, edited by J. H. Simons 1950), pages 66, 524-525.

UNITED STATES PATENT O FKFICE 1 CERTIFICATE ()F CORRECTION Patent No.-f2 ,898,'364' a v A August 4, 1959 James Carroll Conly It is he z 'e' bycertified that error appea rs in the printed specification of the above, numbered patent requiring correction and that. the said Letters (SEAL) I At test il lg'j Patent should read as corrected below.

' Column l,iin e 37, for "phasphate" read phosphate columh 2, line 12, for ,'-'move d" read mixed 'iis ned and s 'ealed this 16th day of February 1960;

Attest:

KARL ,AXLINE V ROBERT (J. WATSON Commissioner of Patents Attesting :Ofiicer Q 7 I UNITED STATES PATENT ()IIIFICE CERTIFICATE OF CORRECTION Patent No.; 2,898-,364 a August 4, 1959 James Carroll Conly It is hereby certified that error appears in the printed specification of. the above numbered patent requiring correction and that the said Letters Patent should readas corrected below.

line 12, for "moved". read-- mixed Column l,rlin'e 37, for "phasphate" read phosphate columrl 2,

. Signed and sealed this 16th day of February 1960.

(SEAL) Attest:

KARL H. X I ROBERT C. WATSON Commissioner of Patents 

1. THE METHOD OF MAKING A PERFLUORINATED TRIALKYL PHOSPHATE ESTER REPRESENTED BY THE FORMULA 